Method of producing compounds of formaldehyde with sugars.



- UNITED STATES PATENT o EIc FRITZ QUADE, or BERLIN, GERMANY, ASSIGNOR To JOHANN ABRAHAM VON or BERLIN, GERMANY.

METHOD'OF PRODUCING COMBOUNDS OF FORMALDEHYDE WITH SUGARS.

No Drawing.

maldehyde under pressure.

I will now proceed to describe my invention:

It is already known to produce such compounds by evaporating in 'vacuo the sugar with an aqueous formaldehyde solution.

But in the preparation of these compounds it has hitherto always. been necessary to use more of the aqueous formaldehyde solution than theoretically required. It has now been discovered that this necessity for excess of formaldehyde can be avoided if the respective bodies are mixed in the proportions necessary for the'reaction in view, provided that the loss of formaldehyde by heating be prevented. This result is obtained by causing the reaction to take place under pressure. In addition tothe saving of formaldehyde, there is a further advantage in being able to raise the temperature up'to 110 centigrade inasmuch as use can be made of the fact that it is not necessary to add the milk sugar which is diflicultly soluble at lower temperatures to the reaction mixture after it has been brought into solution. It. is only necessary in such case to add the 40% formaldehyde solution of commerce to the carbohydrate in its natural condition. By operating in this manner under pressure, the syrups which are obtained when such a carbohydrate is mixed with 40% formaldehyde solution in previously calculatedmolecular proportion and heated under pressure can be brought to. dryness with the lower molecular compounds without perceptible loss of for maldehyde, because-there are only small quantities of water to be evaporated; moreover these lower molecular compounds dissociate.

only feebly and they also give up the water more quickly. On the other hand the removal of the larger quantities of water was cgupled in the case of the compounds richer in formaldehyde, with loss of formaldehyde,

Specification of Letters Patent. Application filed September 16, 1912. Serial No. 720,650.

action an Patented May 20,1913.

which although smaller than when the reac-' tions take place under atmospheric pressure merely, nevertheless disturb the molecular proportions.

I desire to point out, that ithas been proposed (see British Patent No. 6653 of $97) to make av combination ofl molecule of a sugar of the cane sugar group with 1 mole cule of formaldehyde. No reference whatever to'the use of pressure occurs in this specification: the-excess of water is expelled at below 50 centigrade. By this process the syrup cannot. be evaporated to complete dryness and can only be brought into the dry state by mixing with a sufiicient quantity of powdered sugar preferably milk sugar. the particles of the powder so obtained however conglomerate easily together. On exposing this new compound to av temperature of 50 to centigrade, itde omposes back into formaldehyde and sugar, and in the presence of moist air it develops formaldehyde. To render this process workable the patentee proposes to combine the formaldehyde-sugar compound with a haloid alkali, potassic bitartrate, or mixtures thereof. Further, in British Patent No. 25138 of 1909 other methods of producing compounds of malt extract and formaldehyde are set forth and claimed, but there is no reference in this patent also to the use of pressure for retaining the formaldehyde, which forms the distinctive characteristic of the present application.

It has been previously proposed to mingle indifferent materials with the reagents for the purpose of facilitating the drying. It is possible to make use of this'already known method by adding indifferent material (such as powdered talc) to my compounds containing no excess of formaldehyde for the purpose ofabsorbing the water introduced in the form of aqueous formaldehyde solution. The evaporation of large quantities of water is avoided by; my invention when paraformaldehyde of commerce mixed in predetermined proportion with the dry carbohydrates is brought directly into reaction therewith by heating in vessels under pressure to a temperature above 105 centigrade. Such heating produces tough syrups which would present some difiiculty in treatment; but the treatment is facilitated if there has been added at the commencement of the reindift'erent diluting material wtjLFING,

' 2O heated underpressure with 22 parts" of a 40% formaldehyde solution for one hour in the .Water bath, and the small quantity of.

i rial removal offormaldehyde. flAs pressure vessels autoclaves "are used .to a maximum of 2 atmo'sp heres. The exact in the open air;

does not affect the reaction but causes the. production of solid product-swvhich can be easily pulverized. If it be desired to obtain the, products "richer in formaldehyde free from such additions, then the required compounds canbe' produced by aidof mixtures. vof paraformaldehyde' with aqueous solution of formaldehyde.

addedquanti-ty of water. somuch, that-its air at 70 cent, producing the compound 1 1.

heated under pressure with 44 parts of 40% formaldehyde solution in a saline bath up- 'mer'ce are heated with 66 parts of40 for- (powdered talc) which diluting material (See Example 4.) By aid of this method itis possible to reduce'the removal can take place wit 11o11t any'mate which can be brough-t'in the saline bath to a temperature of 110 cent. The pressure-rises.

determination of the pressure is not important, providing no formaldehyde escapes. Example 1:100 parts of cane sugari'are Water. is thenevaporated in 'vacuo or in the -Eg' -ple 2: 100parts of milk g area to 105 cent. The compoundformed is fixed with 300 parts talc, and. is dried-at 70"cent'.f

The mixture contains the compound'lz2p' Example 3 {100 parts ofcane sugar "of cominaldehydesolution under pressure for sevcompound 113 can be extracted up to 110 cent. The compound is then dried at 70 cent. and gives the molecular proportion 1:4. I

'Example'5z. 10 0parts of milk sugar are mixed with '250 parts'of talc .and 44 parts paraformaldehyde of commerce and the hours to temperatures of from 105 to 110 cent. The compound 1:5 is extracted from itith alcohol.

It is understood that ,a formaldehydeforming body may be 'paraformaldehyde' alone or a mixture offormaldehyde and va-' rious polymerization products which are.

usually present in formaldehyde solutions. I claim:

1. The 'process of producing a compound.

containing one molecule ofbiose and one to five molecules of formaldehyde Whichprocessconsists inheatingnthe molecular admixtures ofa formaldehyde forming body and mixture is heated-under pressure for several biose under pressure substantially above atinos pheric at temperatures up to 110 cent.

2. The process of producinga compound containing one molecule of biose and one to fivemolecules' of formaldehyde. which process consists in heating the molecularadmixturesofbiose and concentrated aqueous solu-' tion of a formaldehyde formin'gbody under pressure substantially above atmospheric to prevent escape Of'fOIIIliLldBhYdG, andlremoving the Water by evaporation. r 3. The-process of producing a compound containing" one m'oleculeof biose and one to five molecules of formaldehyde which proces's consists in heating the molecular admixtures-of biose and paraformaldehyde exclusively under pressure substantially above atmospheric, whereby Y indifferent diluting materials such as talcare added to the mass before the commencement of the reaction.

FRITZ QUADE'.

- Witnesses:

EBERHARD THIELEMANN, WALGEMAR- Roses. 

